Many electronic devices, including portable music players, have a microphone input that is typically biased to around 2.3V. The microphone input is typically connected to an external microphone or it may be used as a power source (from its bias); for simplicity, ‘microphone input’ and ‘microphone bias’ will be used interchangeably. In these electronic devices, the microphone and the earphone operate independently. In the case of music players, when music is played (the output is at the earphone output), the microphone, input is often unused and/or when used, it may be used a control input where modulated signals are input for digital control for play/pause and for volume up/down. In telephony applications, an external microphone (as part of a earphone-cum-microphone audio accessory) may be connected to the microphone input.
Examples of electronic devices embodying a music player include a plethora of smartphones and portable MP3 (and variants thereof) players. In such electronic devices, there is no reported easy method in terms of hardware or convenience to estimate (or compute) the loudness and duration of the music/sound exposed to the user of the music player who wears earphones connected to the earphone output of the music player. This loudness and duration constitutes to the noise dosage of the user arising from the acoustical (sound) output from the loudspeaker in the earphone. Safety limits for noise dosage is well established, for example the 1910.95 standards established by USA's Occupational Safety and Health Administration and similar bodies in other countries. When the noise dosage exceeds the stipulated safety limits, the user of the electronic device may suffer from noise induced deafness.
There is no easy method in terms of convenience and hardware because of one or more of the following reasons. First, any added hardware or equivalently a communications (comms) apparatus, for example the inventions delineated in U.S. patent application Ser. No. 12/971,673, requires an external power source (such as an external battery) that would require periodic replacement or charging (external of the electronic device (music player)). Second, the operating system of music players (e.g. in smartphones) does not allow other applications therein access to the output of its digital signal processor/digital-to-analog converter/power amplifier. This lack of access renders the need for hardware external to the music player where the external hardware would need access the earphone output to monitor/measure its electronic signal output (and use the output/input transfer function from the acoustic output of the loudspeaker to its electronic input) or to directly measure the acoustical output of the loudspeaker. Cumbersome/impractical prior-art inventions include US Patent 2009/0208024, US Patent No. US 2010/0278350, etc.
In short, there is no known method to exploit the microphone bias to make it convenient or to reduce the hardware to realize a means of ascertaining the output of the earphone and/or thenoise dosage. The ability to ascertain the noise dosage would increase the functionality of the electronic device (e.g. smartphone as a music player).
The functionality of sophisticated electronic devices, e.g. the smartphone, can be increased by connecting electronics (embodied in a communications (comms) apparatus) whose input is connected to one of the earphone outputs (of the smartphone). In a prior-art invention, the smartphone functions as a remote controller (e.g. for a television), as manufactured by Thinkflood. The remote controller is embodied in a housing with a TRRS connector that is in turn inserted into the TRRS socket of the smart phone. The smartphone outputs a signal via one or both of its earphone outputs (right, left or both audio channel outputs) according to an application in the smartphone. The output signal is thereafter converted by electronics (embodied in the comms apparatus) to an infrared signal that is transmitted. In this prior-art application, the comms apparatus is an intermediary device for a simplex transmission (communication between the smartphone and the television) only by infrared signals. There are two shortcomings of this invention—the limitation of infrared only and the mechanical construction. The limitation of only infrared is probably due to the desired application, and the use of the earphone output thereby disallowing the use of a earphone/headphone. The mechanical connection is simply the insertion of the TRRS connector into the TRRS socket of the smartphone—no mechanical attachment between the housing and the enclosure. As this device protrudes out of the smartphone, it can be broken easily. In short, the functionality is restricted and mechanically weak (easily broken).
Another prior-art simplex transmission is the magnetic induction transmission between a mobile phone (smartphone) and a hearing aid. The transmitter is the magnetic field generated by the loudspeaker in the mobile phone. The hearing aid has a telecoil (T-coil) which generates a voltage from the magnetic field induced from the magnetic field generated by the loudspeaker. The serious shortcoming of this prior-art method is that the magnetic field generated by the loudspeaker is very weak, requiring careful and difficult placement/alignment (require fiddling—trial and error to try to find a ‘sweet’ spot) of the loudspeaker (of the mobile phone) near the hearing aid. In most cases, the magnetic induction remains weak, rendering the simplex transmission unsatisfactory, and the speech intelligibility poor.
In the invention described in U.S. Pat. No. 7,810,729 B2, the microphone input of the electronic device (smartphone) serves as an input and a possible power source. This invention is an intermediary device, a comms apparatus, between the credit card and the smartphone—a credit card reader. The credit card information is read and processed by the electronic device and its output modulated onto the same microphone line—akin to the Play/Pause and Volume Up/Down of prior-art earphone headsets described in U.S. Pat. No. 7,869,608 B2. This invention has a major mechanical shortcoming as in the case of the infrared controller delineated earlier. Specifically, the credit card reader is embodied in a housing with a TRRS connector that is in turn inserted into the TRRS socket of the smartphone, and there is no mechanical attachment between the housing of the credit card reader and the enclosure of the smartphone. The credit card reader protrudes out of the smartphone and is hence mechanically weak (easily broken).
In the invention described in patent application US 2009/0296967, the telephone apparatus (an internal comms apparatus) is part of the telephone set which requires such telephones to be specialized, and the pertinent telephones are typically corded and wireless (DECT) phones. This invention is hence limiting as it is not easily adapted to any phone, particularly smartphones.
In the invention described in USA Patent Application US 2011/0007916, the add-on module (comms apparatus) is largely applicable only to specialized telephone handsets which are not ubiquitous. This is hence not generally applicable nor convenient. Further, the mechanical connection is weak (easily broken).
In the invention described in US Patent 2004/2406892, the intermediary comms apparatus is a cumbersome attachment that includes a microphone to pick up the acoustical loudspeaker output of the phone. The cumbersomeness is largely due to the difficult attachment, large form factor and the electronics therein requiring an external battery.
In the aforesaid inventions and prior-art electronic devices with their associated comms apparatus, the application of the smartphone (and the like) remains limited and often cumbersome, and this is due to a number of reasons. First, in the case of ascertaining noise dosage arising from the audio output of an electronic device, there is no easy means in terms of convenience or in terms of hardware and power source, rendering their realization in large form factor, hence commercially unacceptable. Second, the power available from the microphone bias in the electronic device is very limited, typically <250 microamperes at <2V.
Third, in applications where the microphone input is already connected to a microphone, this input means is largely unavailable as a power source or as an input. Fourth, when data is input into the microphone, the microphone input is not easily applicable as a power source. Fifth, in applications where the earphone output of the electronic device (e.g. smartphone) is already connected to a loudspeaker of earphones (or headphones), this means as an output to the electronics in the comms apparatus is not readily available. For example, the infra-red remote control delineated above cannot be used.
In short, prior-art comms apparatus inventions for measuring the earphone output of electronic devices (e.g. music players in smartphones) and for communications between a first electronic device (e.g. smartphone) and a second electronic device (e.g. hearing aid, pacemaker, etc) are cumbersome and limiting, or mechanically weak (easily broken). Physically, they are often external devices (a separate entity), requiring an external power source, communications are limited (e.g. localized communications instead of more global communications (for example communications between a third electronic device (e.g. a hearing diagnostic system) at one end of the internet, a smartphone (first electronic device) at the other end of the internet, and communications between the smartphone and a hearing aid (second electronic device) via the comms apparatus)), and applicable only to specialized phones, etc.